Replacement of parts of the human face and jaws with manmade materials is the purview of maxillofacial prosthetics. Patients recovering from the surgical effects of skin cancer, oral cancer, traumatic injuries, and birth defects are in need of these services. Existing materials used for this purpose include silicone, polyurethane, and vinyl elastomers. Devices made of such material often fail in a matter of months due to discoloration, fraying of feather edges, sagging, or incompatibility with adhesives. A development program was carried out in 1976-79 at GSRI by Paul D. May and Luis R. Guerra using chlorinated polyethylene (CPE), an industrial elastomer produced by Dow Chemical Company. Limited clinical trials indicated the material to be satisfactory for a more extended trial. This project will continue this work in four parts: 1. Improve the CPE material from its 1979 level and measure its physical and biologic properties using procedure since-developed for use with soft denture liners. Investigate improved phosphate-bonded, or gypsum molds. 2. Perform a pilot study to measure the reliability and validity of: a) tests of material performance, and b) questionnaires of clinician's observations and the patient's perception of existing maxillofacial prostheses. Use this information to modify the test instrument for the principal clinical study. 3. Provide materials and technology to the Dental Department of the Charity Hospital of New Orleans for clinical trials. Twenty patients needing extraoral maxillofacial prostheses will be selected. Each will receive two prostheses, made from the CPE material or from silicone rubber, to be exchanged every 3 months and worn continuously. 4. Compile data generated by the clinicians, the patients, and in the laboratory. Determine superiority of one material over the other by statistically testing the rating and ranking data. The failing prosthesis will be eliminated from the study and the patient will be allowed to continue with the successful one.